HUMAN VERIFICATION REQUIRED ASVS 10.5.5 Back-channel logout validation (when oauth_oidc is used)

When using OIDC back-channel logout, the relying party mitigates denial of service through forced logout and cross-JWT confusion in the logout flow. The client must verify that the logout token is correctly typed with a value of 'logout+jwt', contains the 'event'claim with the correct member name, and does not contain a 'nonce'claim. Note that it is also recommended to have a short expiration (e.g., 2 minutes).